THE NEW TAPPAN ZEE BRIDGE

The long-awaited Governor Mario M. Cuomo Bridge (GMMC Bridge) saw its north-bound span officially opened on August 26^th after four years of construction. The first of the project’s twin two-span cable-stayed structures now caters to automobile transit as well as pedestrian and bicycle traffic.

A $4 billion project, the 5-kilometre bridge replaces its 61-year-old steel truss counterpart, the Tappan Zee Bridge. The GMMC Bridge built at one of the widest points of the Hudson River, connects the New York counties of Rockland and Westchester.

The bridge design features eight 128-metre angled concrete towers, from which 192 stay cables connect back to the main decks. More than 110,000 tonnes of steel and 330,000 cubic yards of concrete were used in the project’s construction, including 6000 precast concrete road deck panels.

Once fully completed, the new bridge will include eight standard traffic lanes with an additional four lanes for breakdowns and emergency vehicles – a component that the current bridge lacks, leading to frequent traffic issues and delays.

According to the Governor’s Office, the inclusion of these additional lanes in could also be converted for future use for bus rapid transit or commuter rail lines. Other sustainable transport design features include the bicycle and walking path that will allow space for six individually-designed resting/viewing platforms.

The project is one of the largest infrastructure projects to use a design-build construction process intended to speed construction time and reduce total costs. Carried out by a consortium of firms known as Tappan Zee Constructors, the project is currently on schedule to be completed on time and $1 billion under initial estimates.

Construction on the eastbound bridge continues to progress, with an expected completion in 2018.

Conceptual renderings of the bridge. Image Courtesy of New York State Thruway Authority